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| author | Michal Hocko <mhocko@suse.cz> | 2012-10-08 16:33:31 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-10-17 03:49:47 +0100 |
| commit | c1bc78797baaf98cb565d0c4afcb8ef26bb28655 (patch) | |
| tree | 91b7f9352d8d791216fd1ee37f94f64d31ba897a /mm | |
| parent | 003be05aed2f27a0ab5f5aadc90a68183f0c6e19 (diff) | |
| download | lwn-c1bc78797baaf98cb565d0c4afcb8ef26bb28655.tar.gz lwn-c1bc78797baaf98cb565d0c4afcb8ef26bb28655.zip | |
hugetlb: do not use vma_hugecache_offset() for vma_prio_tree_foreach
commit 36e4f20af833d1ce196e6a4ade05dc26c44652d1 upstream.
Commit 0c176d52b0b2 ("mm: hugetlb: fix pgoff computation when unmapping
page from vma") fixed pgoff calculation but it has replaced it by
vma_hugecache_offset() which is not approapriate for offsets used for
vma_prio_tree_foreach() because that one expects index in page units
rather than in huge_page_shift.
Johannes said:
: The resulting index may not be too big, but it can be too small: assume
: hpage size of 2M and the address to unmap to be 0x200000. This is regular
: page index 512 and hpage index 1. If you have a VMA that maps the file
: only starting at the second huge page, that VMAs vm_pgoff will be 512 but
: you ask for offset 1 and miss it even though it does map the page of
: interest. hugetlb_cow() will try to unmap, miss the vma, and retry the
: cow until the allocation succeeds or the skipped vma(s) go away.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Hillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/hugetlb.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 31a1a26e52bf..d6c0fdfd8027 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2429,7 +2429,8 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, * from page cache lookup which is in HPAGE_SIZE units. */ address = address & huge_page_mask(h); - pgoff = vma_hugecache_offset(h, vma, address); + pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + + vma->vm_pgoff; mapping = vma->vm_file->f_dentry->d_inode->i_mapping; /* |